The continuous increase in human population density and urban sprawl, has brought with it a steady increase in vehicular traffic volume as more commuters are forced to travel more often and over longer distances on public roads highways to reach their intended destinations. As traffic volume has increased, traffic congestion has also increased thereby leading to an increase in fuel consumption and road wear and a drop in air quality. Accordingly, municipalities and governments have attempted to reduce traffic congestion as a means to reduce vehicle operating costs, road maintenance costs, and air pollution.
The most common approach for reducing traffic congestion has been to use traffic signal lights installed at the intersection of roadways. Typically, the traffic signals use sensors concealed under the road surface in order to monitor and control traffic flow through the intersections. Another approach has been to use traffic cameras and electronic billboards to notify motorists of road conditions and any automobile accidents which may impede traffic flow. An additional approach has been to develop alternate or parallel traffic routes extending between common points. Although these approaches have been widely adopted, they have been ineffective at reducing traffic congestion on a macroscopic level.
For instance, traffic signals are useful when employed on municipal roadways, but cannot be used to control traffic throughput on highways due to the relatively insignificant number of intersections. Typically, traffic cameras must be monitored by human operators, thereby introducing a delay between the recognition of a traffic problem and the notification thereof to the appropriate motorists. Also, billboards typically can only suggest that motorists select a single alternate route when a traffic problem develops on one route. As a result, notification of a traffic problem on one route often causes a traffic problem on the suggested alternate route. The construction of additional parallel traffic routes is limited by budget limitations of the municipality or government. Although road tariffs or tolls can be used as a means to fund the construction of such routes, commuters are often reluctant to use toll routes when non-toll routes are readily available.
Consequently, there have been many attempts to address the problem of traffic congestion, however the solution to this problem to-date remains largely unsolved.